going to use the accelerometer as a seismic detector,
I recommend you use D batteries so you won’t have to
change them so often. D batteries should last about a
The chip can be programmed or re-programmed
repeatedly using a Microchip PICkit 2. The square pad
is pin 1 for the programmer. There are only five pins
needed (the sixth is redundant).
The container is made out of a 1.4” piece of 2. 5” EMT
PVC pipe. Both the top and the bottom of the pipe should
You will find a template for the Plexiglas lens at the
article link. Cut it out and glue it to a 1/4” piece of
Plexiglas. Sand the Plexiglas to the edge of the circle.
36 November 2014
HINTS & TIPS FOR THE
To view and change the board files and schematic,
go to www.expresspcb.com and download their free
CAD software. There is no obligation and you will not
be harassed by emails.
Microchip provides free software for programming
their microprocessors at www.microchip.com.
MISSING PARTS LIST
The following parts are not needed:
R1, R2, R4, C1, IC1
These were used with the "Poor Man's
Seismometer" published in the Nuts & Volts May 2012
DOs AND DON'Ts
If data won't record on the SD card, check to see
(with Notepad) if Accel1 is corrupt. If it is, reformat the
SD card and add time.txt.
If no file recorded on the manual setting, make
sure you stop it by pushing the button. If you just turn
off the power, the file will not close.
If the green LED doesn't flash, make sure the SD
card is in place and locked.
When using a high g impact, I recommend using
solder tab batteries. When mounted in the battery
compartment, they tend to break contact upon impact
and reset the machine. The red LED will turn on if this
Although both chips have the ability to collect
data up to 1,600 Hz, do not exceed 50 Hz as writing to
the SD card along with the micro won't keep up.
When using continuous mode, be aware the unit
pulls 25-30 mA Use a hefty battery for long runs.
I use the new Notepad++ for viewing raw data. It
is free software.
USING THE WINDAQ WAVEFORM BROWER:
To view the data, go to www.dataq.com and
download their free software titled WinDaq Waveform
Browser (Figure A) under downloads. For those that
are interested in great data loggers and data
acquisition, I can't say enough good things about
WinDaq. The browser is also located at the article link.
WARNING: YOU MAY HAVE TO REMOVE THE
HEADER INFORMATION FOR THE FILE USING
Once the Waveform Browser is downloaded, there
should be an icon on your computer; click this icon.
A window should open up. Locate the SD card and
make sure you have Files on the *.txt type. Look for
the Accel1.txt file or other numbered seismic
files.Click on this. Save Accel1.wdc (default). Use the
#15 spreadsheet print file (ASCII) with fixed scale. Add
an "a" after the file name and save. The convert screen
should pop up with “Translating 3 Channels.” Put in 50
for the sample rate per channel and the default on
volts. Hit the return key. (This is subject to change
depending on what version you have of the browser.)
The Waveform Browser should now be visible. If
you go to Options and click on Cursor Time, the date
and time will show at the bottom when an earthquake
happened. Moving the cursor below the red line will
show the time. By pressing F4 to place a time marker,
you can measure from the time marker the seconds
from an event.
You can increase the amplification by centering
the wave form (Z axis), changing the voltage:
1. Place the cursor on 3= 3 and right-click.
2. Hold down the right button and make a box
around the first data.
3. Drag the box so that the data is approximately
at the center line.
4. Put the curser back on 3= 3 and right-click; this
will reduce the spread voltages.
There is a plethora of commands you can use in
the WinDaq browser, so I defer you to their help menu
as it would take a small book to explain them all.
Once you have downloaded your data, delete all the
Accel.txt files on the SD card to re-record.
Have questions? Write or call me.
1035 Haystack Dr.
Carson City, NV 89705
■ FIGURE A.